Chapter 88: Catalytic converters
A catalytic converter has to be at least how hot before it begins to work? 500 degrees F 1,000 degrees F 1,500 degrees F 2,000 degrees F
500 degrees F
A catalytic converter can be harmed by ________. sulfur from poor-quality fuel excessive engine oil antifreeze Any of the above
Any of the above
A P0422 (catalytic converter efficiency failure) is set. What is a possible cause? Engine mechanical fault Fuel contamination Exhaust leak Any of these
Any of these
Some vehicles have a "mini converter." Where is this component located? Just upstream of the muffler Attached directly to the exhaust manifold Downstream of the main catalytic converter None of these
Attached directly to the exhaust manifold
Technician A says that the catalytic converter is warranted for 8 years or 80,000 miles, whichever comes first. Technician B says that after replacing the catalytic converter, the old converter must be kept for possible inspection for 60 days. Which technician is correct?
Both technicians
Two technicians are discussing the testing of a catalytic converter. Technician A says that a vacuum gauge can be used and observed to see if the vacuum drops with the engine at 2500 RPM for 30 seconds. Technician B says that a pressure gauge can be used to check for backpressure. Which technician is correct?
Both technicians
Which exhaust gas reading indicates a good catalytic converter? CO is zero O2 is zero Both A and B Neither A nor B
CO is zero
What term describes a catalytic converter as it reaches its effective temperature? Consumption Initiation Light off None of these
Light off
Technician A says that the location of the catalytic converter is not important. Technician B says that the catalytic converter should be positioned as far from the engine as possible. Which technician is correct?
Neither technician
What two primary sensors does the PCM use to check the catalytic converter? Pre-cat oxygen sensor and MAF Pre-cat and post-cat oxygen sensor MAP and TP Catalytic converter temperature sensor and rear oxygen sensor
Pre-cat and post-cat oxygen sensor
The addition of cerium to catalytic converters provided what benefit? Purification of NOx Stores oxygen to help with the oxidation process Reduction of NOx None of these
Stores oxygen to help with the oxidation process
Two technicians are discussing catalytic converters. Technician A says that the exhaust should have a 14.7:1 air-fuel ratio for the best efficiency. Technician B says that the air-fuel mixture must be leaner than 14.7:1 for best performance from a three-way catalytic converter. Which technician is correct?
Technician A only
A catalytic converter is being tested with an infrared pyrometer. Which is an acceptable (good converter) result? The inlet should be hotter than the outlet by 10% Both the inlet and outlet should be the same temperature after the converter reaches operating temperature The outlet should be hotter than the inlet by 10% The temperature of a catalytic converter is the best test to perform to locate a restricted unit
The outlet should be hotter than the inlet by 10%
What is applied to the ceramic substrate to make the surface porous? Honeycomb filler Aluminum Cerium Washcoat
Washcoat
All these are causes of catalytic converter failure EXCEPT ________. air-fuel mixture set at 14.7:1 ratio raw fuel in the exhaust excessive temperature antifreeze in the exhaust
air-fuel mixture set at 14.7:1 ratio
